Insurance companies are also a source of "non-government infringement". A year or so ago, a gun store here in Farifax, VA was forced to close because the landlord's insurance company found out there was a gun store on the property and jacked up the landlord's liability insurance. The gun store had plenty of liability insurance. It was the insurance company of the restaurant owner landlord who forced the store to close.
I am convinced that insurance pricing practices are responsible for more than a few anti-gun regulations adopted by employers and forced upon their employees. Employers are looking for the cheapest insurance, so if an insurance company says they can save x% on liability premiums by inserting "no firearms possession on company property" language in employment contracts and employee handbooks, they're going to go for it.
Insurance companies are responsible for all of the "no loaded firearms" rules in place at the Virginia gun shows I have attended. If the promoter can't get insurance unless he prohibits loaded firearms, then there will be no loaded firearms at the show.